This Week on perl5-porters (1-7 March 2004)
This week was one of those weeks where the bug reports outnumbered the
bug fixes. Hopefully in the future the perl 5 porters will be able to
keep perl 5 on the right track, as they continue to do, week after week.
5.005_04
Leon Brocard released perl 5.005_04, the latest perl in the 5.005
series. The official announcement is at :
http://groups.google.com/groups?selm=20040301142712.GA24155%40kanga.astray.com
Setting $!
Following a thread about an update to the perlxstut manpage that Marcus
Holland-Moritz is writing, there was some interesting discussion about
the proper way to set the $! errno variable from user code, whether this
is a good idea, and how the PerlIO system handles it. Nick Ing-Simmons
points out that $! is actually the C variable errno, and that perl
stringifies it via strerror(3) when used in string context; and thus
that it shouldn't be set to custom values and error messages.
http://groups.google.com/groups?selm=40453C56.1050501%40stason.org
About the debugger
Richard Foley added a couple of commands to the perl debugger: "save",
to save the current history to a file, and "i", which prints the
inheritance tree of its argument (if "Class::ISA" is installed.)
Chip Salzenberg finds out that the perldebugger sometimes hangs when
it's back from a pager. Richard believes it's a known bug, but Chip is
using the most recent 5.8.3 from Debian.
http://groups.google.com/groups?selm=20040303213506.GO10904%40perlsupport.com
More on the famous lexical-in-conditional deprecation warning
Finally, Rafael changed his mind and preferred that
my $x if $foo;
doesn't warn anymore, and that only
my $x if 0;
does (clearly an abuse of the current accidental feature). The new form
of this warning, implemented by Dave Mitchell, is now "Deprecated use of
my() in false conditional".
Range operator edge cases
Marcus Thiesen began to notice that "undef .. undef" produces a segfault
with perl 5.8.x. Marcus Holland-Moritz provided a patch, but later tried
some combinations with "undef" or an empty string at one or both ends of
a "..", and posted his conclusions (along with other bugs found and
fixed) with some questions (what should "undef .. undef" and other
strange combinations return?)
http://groups.google.com/groups?selm=20040307211120.10e46933%40r2d2
readline() and PerlIO slurp mode
Stas Bekman remarks that, in some cases, localising $/ isn't taken into
account, because he observed that when doing
print <$fh>;
print() is called as many times as there are lines in the file opened
via $fh. Contrary to the first thoughts, this is unrelated to scalar
context versus list context, but to some internal flags in PerlIO. Stas
then admits to be unable to reproduce the mysterious problem after a
perl upgrade.
http://groups.google.com/groups?selm=4047E7B3.8040106%40stason.org
Some Bugs
Yves Orton produces an error "Attempt to free unreferenced scalar" by
blessing an anonymous glob (bug #27268), and by assigning the glob
reference to the glob itself:
perl -MSymbol -e 'my $x=bless \gensym,q/t/; *$$x=$x'
Bug #27344 shows a pos() bug which happens only when taint mode is on.
http://groups.google.com/groups?selm=rt-3.0.8-27344-80480.18.8941338152323%40perl.org
Lukas Mai remarks that the "(;$)" prototype doesn't mimic closely the
way length() is parsed, making it impossible to override fully. (Bug
#27380.)
http://groups.google.com/groups?selm=rt-3.0.8-27380-80726.0.626385108255718%40perl.org
Ton Hospel finds that returning the special arrays @+ or @- from a
subroutine don't appear to work correctly. (no bug number for this one.)
http://groups.google.com/groups?selm=c26p20$34b$1%40post.home.lunix
In Brief
Dave Mitchell explains that closures are broken "by design" inside
"/(?{...})/" blocks.
http://groups.google.com/groups?selm=20040306155204.GA18953%40fdisolutions.com
Jarkko Hietaniemi provided a patch to significantly speed up
case-related operations with UTF-8 strings (lc(), uc(), //i, etc.).
Christopher Madsen reported that Win32::GetOSVersion() was recently
broken. It was repaired by Steve Hay. (Bug #27357.)
About this summary
This summary was written by Rafael Garcia-Suarez. Weekly summaries are
published on http://use.perl.org/ and posted on a mailing list, which
subscription address is [EMAIL PROTECTED] Corrections
and comments are welcome.
